This invention relates to a coupling that is suitable to join together a pair of elements having juxtaposed radial flanges including pipes, hoses, tubes or the like and is particularly suitable for joining a turbo-charger end housing to a turbo-charger center (or bearing) housing and for joining a turbine housing to an exhaust outlet connection.
Couplings for joining together pipes, hoses, tubes and the like are extremely well known and can take a variety of forms. For example, the coupling illustrated in U.S. Pat. No. 1,442,909 to Ryan is designed to attach a relatively flexible hose onto a relatively stiff pipe telescopically received within the flexible hose and includes a pair of arcuate sections pivotally connected at one end. The coupling further includes a yoke type fastener for linking the opposite ends of the arcuate sections to form a closed loop that is adapted to be circumferentially reduced by means of the yoke type fastener to cause the arcuate sections to radially squeeze the flexible hose onto the pipe. While suitable for its intended purpose, this type of coupling is limited to situations where the elements being joined are telescopically arranged and the outer element is relatively flexible to permit the outer element to be squeezed onto the telescopically received element.
In many situations the elements to be joined are relatively inflexible metal tubes or assemblies that require end to end joinder of the elements either directly in abutting contact or with an intervening gasket to improve the fluid tightness of the joint. This type of end to endjoinder is particular useful in joining together elements of a turbocharger assembly such as a center (or bearing) housing to a turbine housing or the turbine housing to an exhaust outlet. Examples of these types of prior art couplings are illustrated in U.S. Pat. No. 5,509,702 to Warehime et al. and U.S. Pat. No. 5,653,481 to Alderman both of which disclose couplings that are designed to join together pipes having radial flanges adjacent the pipe ends. Each coupling is designed to impart an axial force to the radial flanges to cause the pipes to be forced together into end-to-end abutting relationship. The patent to Warehime et al. ""702 discloses a pair of arcuate jaws having inwardly opening grooves for receiving the juxtaposed radial flanges of the respective pipe sections. The inner surfaces of the grooves are flared to create camming surfaces that force the pipe ends together axially as the coupling jaws are drawn together by a fastener that pulls together the free ends of the jaws. The other ends of the respective jaws are linked together by a multi-element assembly that forms two separate pivot connections for the arcuate jaws respectively. The patent to Alderman ""481 discloses a similar arcuate jaw arrangement but the jaws are hingedly joined along a single pivot axis at one end and pulled together at their opposite ends by means of a bolt and nut assembly. As illustrated in FIG. 4 of the Warehime et al. ""702 and FIG. 2 of the Alderman ""481 patent, a seal or gasket may be placed between the respective flanged elements being joined by the clamp to assist in forming a seal.
While couplings disclosed in both Warehime et al. ""702 and Alderman ""481 are suitable for the purposes disclosed, these patents illustrate relatively complex (and therefor expensive) coupling structures that are not suitable, for situations were low cost is essential to achieving the desired result. U.S. Pat. No. 5,570,499 to Katayama et al. overcomes some of the problems associated with high cost and complexity in a bolt-tightened coupling for joining flanged elements together in abutting end-to-end relationship. In particular, Katayama et al. ""499 discloses a coupling including a pair of jaws that includes an extension flange at one end of each jaw to form an arcuate tab extending through a connecting ring 4. This type of connection is similar to the hinge structure illustrated in the Ryan ""909 patent cited above and could give rise to the possibility of failure should either arcuate tab become unbent during the tightening process. Katayama et al. ""499 also discloses the concept of mounting the fastening bolt that allows limited rotation to assist during the installation process but suggests a variety of different arrangements of xe2x80x9cprojectionsxe2x80x9d for engaging the shank portion of the fastening bolt. These projections provide some level of retention of the bolt but do not insure that the fastening bolt will not be lost or separated during the assembly process should the bolt be subjected to a dislodging axial force.
Swiss Patent No. 285,561 discloses a coupling having a pair of arcuate members that are rotatably joined by hinge means formed from a hook shaped extension located at one end of a member extending into an opening located at one end of the other member. The arcuate members are pulled together by means of a threaded fastener arranged to engage a pair of radial projections located at the ends of the arcuate member opposite the hinge. While useful for the purposes disclosed the coupling illustrated in this patent does not include arcuate jaws having radially inwardly opening grooves for engaging the juxtapositioned flanges of a pair of flanged elements.
An object of this invention is to provide a coupling which overcomes the deficiencies of the prior art and more particularly, a coupling for joining a pair of flanged elements which is both high in strength yet low in cost.
A more specific object of this invention is to provide a coupling for releasably joining a pair of flanged elements having juxtaposed radial flanges wherein the coupling includes first and second arcuate jaws pivotally joined by a hinge connection at one end and biased together by a jaw fastener at the other end wherein the hinge connection is formed by an extension of the second arcuate jaw and is arranged to pass through an opening in the first arcuate jaw and is curved back upon the second arcuate jaw and affixed thereto to form a closed loop pivot for the hinge connection.
Another object of this invention is to form each of the first and second arcuate jaws with an arcuate peripheral wall and a pair of radially inwardly directed side walls connected to the arcuate peripheral wall to form inwardly opening grooves wherein the side walls have inner surfaces defining the axial boundaries of the radially inwardly opening grooves. The inner surfaces are oriented to cause the axial distance separating each pair of inner surfaces to be greater at the mouth of the groove as compared with the axial distance separating the inner surfaces at the base adjacent the peripheral wall. The inner surfaces are arranged to contact the radial flanges of the flanged elements to impart the axial biasing force to the flanged elements.
Yet another object is to provide each arcuate jaw as described above with a radially outwardly extending end projection wherein the end projections are arranged in spaced apart juxtaposed position when the first and second arcuate jaws are in their closed position and wherein the jaw fastener includes an elongated shaft axially retained at one end with respect to the other end projection yet free for limited rotation to allow the elongated shaft of the jaw fastener to pass through an aperture formed in one of the projections during movement of the first and second arcuate jaws between open and closed positions.
Still another object of this invention is to provide a coupling as defined above wherein said elongated shaft is threaded at its distal end and the jaw fastener includes a threaded nut having mating threads to cause the first and second arcuate jaws to be pulled into their closed position upon rotation in one direction of the threaded nut and to move toward their open position upon rotation in an opposite direction of the threaded nut.
Another object of this invention is to provide a coupling as described above wherein the elongated shaft includes a head and one end projection of an arcuate jaw includes a retaining tab for engaging the head to limit axial movement of the elongated shaft while permitting limited rotational movement of the elongated shaft when the first and second arcuate jaws are moved between open and closed positions.
A more specific object of this invention is to provide a coupling as described above wherein the end projections are curved back toward the first and second arcuate jaws, respectively, such that the distal ends of the end projections may be affixed to the first and second arcuate jaws, respectively, to form closed loops for retaining the head and the threaded element of the jaw fastener to thereby aid in simplifying the assembly process.
Another more specific object is to provide a coupling as described above wherein the end projection which retains the threaded element contains a second aperture through which the elongated shaft extends.
Yet another object is to provide a coupling as described above wherein the head of the elongated shaft includes a pair of radial head projections extending radially with respect to the central axis of the elongated shaft, and wherein the one end projection of the arcuate jaw to which the elongated shaft is axially affixed contains depressions on opposite sides of the first aperture to receive the radial head projections in an orientation to permit limited rotation of the elongated shaft in the same plane as the plane of rotational of the first and second arcuate jaws. The elongated shaft may be a T-bolt and the elongated shaft may be mounted to be free to rotate toward the hinge connection by an arcuate distance that is at least great enough to permit its distal end to enter the first aperture as the arcuate jaws are moved from their fully open position toward their fully closed position and to rotate away from the hinge connection as the arcuate jaws continue to move to their fully closed position.
It is another object of the disclosed invention to provide a coupling as defined above, wherein the first and second arcuate jaws are formed of stamped sheet metal having a material thickness of approximately 1.0 to 4.0 millimeter, and wherein the sidewalls of the arcuate jaws extend from the hinge connection to the end projection of each arcuate jaw.
Another object is to provide a coupling as described above, wherein the sidewalls extend around-the entire perimeter of each end projection and join together at the distal end of each end projection to form a single continuous reinforcing wall extending along substantially the entire length of each said arcuate jaw and wherein the sidewalls of the first arcuate jaw are flared out to form a lateral enlargement in the axial direction of the first arcuate jaw adjacent the opening to allow the dimension of the opening in the axial direction to be equal substantially to the axial width of the peripheral wall of the second arcuate jaw and still further wherein the extension of the second arcuate jaw has substantially the same axial width as said opening contained in the first arcuate jaw.
Yet another object is to provide a coupling as described above including a threaded nut permanently affixed to one of the end projections and further including a threaded bolt extending through the other end projection for engagement with the threaded nut to retain the arcuate jaws in their closed position wherein the bolt includes an unthreaded, reduced diameter distal end to provide self piloting during the assembly process and wherein the side walls of the arcuate jaws are interrupted at about their mid points to provide added flexibility to allow the coupling to adjust to irregularities and misalignments of the assembled components.
Still other and more specific objects of this invention may be understood from the following Brief Summary of the Drawings and Detailed Description of the Invention.